I think it will make quite a difference to high speed runs. The bike is very narrow compared to other liter bikes and this leaves the rider more exposed to the airflow. Ducati spent time in the wind tunnel trying to deal with this and the fact that organic part of the bike/rider combination isn't at all aero dynamic. These winglets help guide the air around the bike and rider to reduce drag. Drag saps energy as the square of speed - the effect of drag is 100 times greater at 100mph than it is a 10mph (x400 and 200mph). This is why 1200 bhp supercars can only manage an extra 50 mph, desipte low drag coefficients.

That said, the aero extensions look fugly and won't make a blind bit of difference unless you you rotinely spend time north of 250kph. Might be woth fitting for track days. Besides the aero effect, they could be consided sacrificial body work, think of them as faring sliders. There seems to also be some concern that they'll rub/mark the borywork underneath. I'd put some 3M film between them and the fairing before fitting.